THE GAMETES IN PLANTS AND ANIMALS 



345 



genie, male-producing, and the zygogenic, female-producing, eggs 

 have, so far as I am aware, been described. But the morphological 

 differences in the daphnids and plant lice are evidently extreme, 



FIGS. 183-185. Fig. 183, ovary 

 of Plumatella (bryozoan), showing 

 eggs in various stages of growth 

 and differentiation. From Braem, 

 '97; Figs. 184, 185, growing egg 

 of Sternaspis (annelid), attached 

 to a stalk which contains a vas- 

 cular loop; full-grown egg. 



and it is possible either that much less conspicuous morphological 

 differences exist in the bees, or that the physiological differences 

 are so slight as to be morphologically inappreciable; probably 



